Facsimile recording apparatus



l Aug. 29, 1950 G. J. GIEL, JR

FACSIMILE RECORDING APPARATUS 3 Sheets-Sheet 1 Filed Aug. 7, 1946 G. J. GIEL, JR

FACSIMILE RECORDING APPARATUS Aang'. 29, 1950 s sheets-sheet 2Y Filed Aug. '7, l1946 Eig@ momm 332m Aug. 29, 1950y G. .Leu-:1., JR

FACSIMILE RECORDING APPARATUS Filed Aug. '7, 194

5 Sheets-Sheet 3 w M w LA/em Patented Aug. 29, 1950 UNITED STATES ii'A'I'EN'I QFFICE 2,520,761 g l FACSIMILE RECORDING APPARATUSv George J. Giel, Jr., Flint, Mich.

Application August 7, 1946, Serial No. l688,903

2 Claims.

The present invention relates to an apparatus for facsimile recording and graphic expansion of originals and the like, and particularly to an apparatus reproducing originals on enlarged cr reduced scale using electronic circuits.

In the art of vfacsimile recording, the original is broken up electrically into separate small elements and transformed into electrical impulses which are transmitted to a recording unit and there reassembled into their original position to form a reproduction of the original.

'IWc methods are commonly employed for the purpose of receiving and recording the electrical impulses originating in photo-electric units which are used for scanning the original deposited upon a scanning drum. In one case, the reproduction is accomplished by the use of a marking head carrying a stylus or engraving tool; where a stylus is used, the record is made on electrolytic recording paper, which paper is well known to the art and in wide use. In the other case, a marking bar and helix Wire, which Wire is disposed in one helical turn about the axis on the surface of a recording drum, is used for recording the copy on electrolytic recording paper,

An important part of the receiving operation in systems using either method is the necessity of synchronizing and phasing, or meshing, of the transmitting andreceiving units of the apparatus, and particularly the meshing of scanning and recording heads and scanning and recording drums respectively.

While in tele-facsimile systems the stations are meshed by electrical means, in stationary vfacsimile recording units, scanning and recording assemblies are meshed by mechanical or electrical means. Inaccurate synchronization will result in distortion o f the copy.

It is one of the features of the present invention to control the distortion resulting from the rotation and movement at different speeds of the scanning and recording assemblies respectively, facilitating thereby the enlargement or reduction in size of the recordedl copy with respect tothe original, and also permitting a controlled distortion in width or length only of the re` corded copy in any desired proportion.

' A primary object of the invention is therefore t'o provide an apparatus for facsimile recording and the like, which will permit the graphic exsy pansionof the original on the recorded copy resulting in the enlargement or reduction of the recorded copy in any desired ratio to the size ofthe original. A further object is to provide an apparatus of the class described which is simple in construction, inexpensive to bui1d,andfadA justable' to facilitate a controlled horizontally or vertically distorted reproduction of an original, and at the -same time produce reproductions of high accuracy and durability. AA still furtherobject of the invention is to provide an apparatus for facsimile recording which will produce object lines vof original drawings, but will` entirely elim;- inate intransmission project lines, construction lines and other undesired smudges, resulting in a clean copy of improved appearance over the original. -A still further object of the present' invention is to provide an apparatus adapted to reproduce ink or pencil drawings on templetsr of any desired size proportionalto the size of the original. n

Additional objects, together with further advantages derived in utilizing the present invention, will become apparent from the following de`' y tailed description thereof taken togetherY with' thevaccompanying drawingsvforming part of the specification, in Which similar v,characters of refe'rence represent corresponding parts inthe sev-l. eral views: y

Figure 1kv is a schematic diagram of a facsimile recording apparatus using a recording stylus and embodying features of the present invention, Y

Figure 2 is a circuit-Wiring diagramV of the smudge rejector shown in Figure l, V i

l Figure 3 is a graph showing theamplier out? put and vsmudge rejector output in relation .to

correspondin'gareas viewed by the photo-electric` scanning head of Figure l,

Figure 4 is a schematic diagram inperspec., tive vof a facsimile yrecording apparatus with marking bar-helix Wire recording mechanism, and embodying in modified form, features of the present invention.

Figure 5 is a circuit wiring diagram of the balanced modulator shown in Figure 1.

Figure 6 is a circuit Wiring diagram of the scanning head shown in Figure 1.

Figure 7 is a circuit lWiring diagram drum in the perspective.

Referring `to the characters oi reference.Nonv

the drawings, vs /hereinl for the purpose of illustration is shown apreferred embodiment of my 3 having a diameter;` twicethat of the scanning drum l, and secured to va shaft 4, a suitableA coupling 5 connecting driving shaft 2 to shaft E, 'y

electrical driving vmeans effecting the axial v fof the helical recording circuit, showing the Vreceiving n movement of the said shafts and determining the resulting angular velocity of scanning drum I and recording drum 3, said electrical driving means comprising a spur gear 6 secured to driving shaft 2 and engaging a Worm gear 1, which latter Worm gear is keyed to motor extension shaft 8 and driven by electric motor 9.

A scanning head IIl is disposed radially and in spaced relation to scanning drum I and movable axially to .said dr-.umoby means rofl a tapped split nut or the like mountedinside the scanning head and suitable to engage a threaded shaft II extending through said split nut and positioned axially along the surface of scanningA drumli. A guide rod I2 also disposed axially along the surface of scanning drum I passesinlr-sliiable relation through a suitable sleevesmountedimY side the scanning head I0, and 'holds' said`scan'- ning head in a iixed tangential relation...to-tli`e scanning drum I. y

The. marking. heads I3-.fdisposedf..radially and.. in. spaced relatiomto recording drum3 andmovableeaxially to 'said=.ci-`1u1m,.v comprises af-tapped split nut-orthelikesuitable to engage athreadecs shaft-.Ill'rextending throughnsaidssplit nut and disposed aXially-along tl-iesurface.of+thereeordingdrum. 3,.- and a.--suitable sleevethroughwhich. passes inslidable relationf-.afguiderod- I5 disposed axially along thersurfaceorecording; drum' 3.1: andvfholding thetmarkingv. head. I3 yitt-fixed' tangentialrelationto recording drum. 3-.

The threaded. scanningr, head carrying shaft IIy is-driven ibyftheelectricsmotor 9*. through a. gear. transmission.. comprising .a spur.. gear I 6: keyed-.toshat-t II, and: engagingfalworm-.gearil secured to motor extension shaft 8.

A variable lspeedi :transmission positioned s betweenK threaded scanning'head-.carryi-ng shaitdl and .threaded .recordingfheadV carrying .shaft .I 4,, comprises,. in` the. embodiment o.- the invention:l shown in-.Figure1,..a..:driving.'spur.. gear. l8r mountedmon. .the n extremityofshaft I I e anda; driven spun gear.- I lmountedon. the end-.of shaft I4, resulting in the axial rotation of-.thesaid shafts.. at determined. differentiaL. speeds and thereby causing rscanning head I 0 .and marking head I3 gto-.move .axiallyw on theireepective shafts. atworresponding speeds.

The scanning head -lrwellknownnto the-art... normally comp1:ises...a..sourceofv light` adapted throughoptical means .taco-ncentratea spot Vof.- light on thescanning drlum.=.l andl.optical means.. collecting and deliveringrthe reflected .light raysv to..a...photo.e1ectric .celh The scanning. head, I 9, illustrated. irL.Figure=:6,./,consists..ot'a source ofi light ..1 I,; a.lens.12,.` coxzicentrating-al spot ofv light.. on the scanning drum:.I,f andolenses13-and 14,. collecting and delivering the reflected ligl'itto-a photofelectric .cell 15.. The.:electrical limpulses produced by the..photoelectric collare-.transmittedto a..balanced=;modulator 2D, which latter may be of standard-.design and will. compri-se a. balanced .resistance-.capacitance bridge so constructed.. that la.. change of. .the amount of light. entering the photo-electricfcellproduces an un balancein :said .bridge .and hence: am resultant amplitude .modulation of. Ea .signal originating inw the audio oscillator. 2 I.. The audio .oscillator 2 I f maybe .of standard .desigmxdeliveringf a continu ous. sinusoidal signal .to thebalanced4 modulator 2 Il In .the embodiment of. the invention. shown: in.. Figure -1,- the balanced. modulator was used to facilitate thefuseof` alternatinglcurrent ampli catiom. Provision-is alsozmadeinvsaid balanced` modulatonf 2lb-for the .manuaLcontrol fof ther:

original balance of the resistance-capacitance bridge, and control of the direction of unbalance so that an increase in the reected light from the original produces either an increase or decrease in signal output as the recorded copy .is desired to appear either as a positive or a negative.

The output of the audio oscillator 2| is fed into the resistance-capacitance bridge 6I) through transformer B'I The resistance-"capacitance bridge Geconsists of potentiometers EZ'and 53' with balancing resistere 64 and variable capacitor 65.

The:outputiofiphoto-electric cell 15 is fed into the resistance-capacitance bridge, as shown in Eigure The output of the resistance-capacitance bridge Gil is .connected to the control grid 1`of the istamplifier tube 68, of an aperiodic amplifier 1:22 of standard design.

In operation, potentibmeters 62 and 63 are used. to` adjust the. amplitude` of-..theielectrical-.im pulsesy :which` pass through; .the bridgev 60.-: conf. trolling vini eieett theamount of soriginal AunbalR ance, The directioncofthis.unbalance deterl mines Whether an increasing.- impedance= of-fthey photofelectric cell' .by scanning'lfa aw-hite area for. example. .will .resultinueither an. increase or decrease of .the potential' oi .the grid t61 .of' thev first amplifier tube- 68.

The=resistanceecapaoitancebridgeB9:is-initially unbalanced insonedirection Jor thepther, andva changeof.v the impedance. of f thefphotoelectric cell-.15..with-incident lightlfurthers-.the unbalanceandproduces :thereby a greater :amplitude .output from..the .resistance-.capacitance bridge. 601.111 theoriginal-.unbalance .isfirn one direction? the in. creasein :light on: the photo-electric.cell.f15f:pro duces a..decrease in. amplitudefandif .-the-.bridge: is originally .unbalancedl invthe opposite-direction-,- increasing,, light: will.. produce an. increase im amplitude.r The.. potentiometer controlsfllanda 63 :will: .therefore permit the .production .of either positive. or negative.. prints;r The. output.-of..the:- amplifier. '22, shown graphically ini .Figure r 3f .is fed into the` smudge :rejectcr-ZSH Thefsmudga rejector zcircuit,..illustrated.ini Figure i2,.hasrfor Jits purpose. ther. elimination of.: undesired .smudgesi and. lines.. appearing:A onl thesoriginal A from; the recorded copy.- Inthis-circuialeadt connected: to .theoutput terminal of'aperiodicamplifler 22,: passes through the smudge rejectorf" 23 andY .is-i coupled to power amplifier 21.-. The. other-1ead-r- 50. connectsy the other output .terminal .l otaperiodic-` amplifier.. 22 .to tlieanodetof` .diode 4 Land through` .-a capacitors. 53-1 and. its..by pass .resistor- 54... The #cathode `of-.diode` 4 I -and..-they anode of diode 42 are connected to the.adjustablecontacty of .potentiometers .44 `and v45..respectively.through xed .resistors 55 and 56" respectively.` and rto: ground through. byspass capacitors .46 rand1 441 reff spectively. Battery, .eB--is-.connected across :po-h tentiometers-M and- 45,. the `common. terminals 1 ot '2 said.. potentiometers fbeing..4 groundedf.. ande. supdiode .tube 43... Lead;- .52, connected totheanodef of diode 42 `through-- mixing. resistor .51 andato' the .cathode= of `diode Y 4 I. througlf. mixing .resistor 58, islcoupledtd the..nput..terminal of'. power@ ampli'erll. Potentiometercontrols-.44 and 545e permit .the :adjustment of. .the `bias and hence-:the:v controlledlimiting of theamplitudebf the signal currents'.k applied-to=duab iiode-t;ubevll3i4 The'v potentiometer controls etogetlierlwith .the manual. contrast controlsfiofn: theffresistance-feapacitanc bridge of the balanced modulator 20, constitute the smudge rejection system.

The output of the smudge rejection circuit is shown graphically in Figure 3, where it is shown that the circuit eliminates signal current amplitude changes below a predetermined level and passes signal current amplitude changes above that predetermined level. The amplitude level to which the smudge rejection circuit will be adjusted, will depend upon the strength of the electrical impulses produced by the photo-electric cell, which electrical impulses will be stronger for object lines on original drawings and the like. and weaker for construction linesand other undesired smudges.

The output of the smudge rejector is fed by means of leads 5I and 52 into power amplifier and matching circuit 21, which latter power amplifier and matching circuit may be of conventional design. The output signal of the power amplifier and matching circuit 21 is then applied to the marking stylus of marking head I3. The passage of the current between the marking stylus and the grounded recording drum 3 through an electrolytic recording paper produces a mark on said paper corresponding to the markings viewed by the photo-electric cell located in scanning head I0.

In operation, the original is placed on scanning drum I. When said drum is rotated at a determined speed, scanning head Il! travels axially along scanning drum i, scanning the original, a process well known to the art. The electric impulses originating in the photo-electric cell, located in the scanning head IG, are then transmitted through the electronic transmission circuit described above, to the marking stylus of the marking head I3.

If a 2:1 enlargement is desired, the gear ratio of driving spur gear IS to driven spur gear I9 must also be 2: 1, and the diameter of the recording drum 3 must be twice that of scanning drum I. In this case, marking head I 3 will travel axially along recording drum 3 at twice the speed relative to the lateral movement of scanning head Ill, resulting in a 2:1 enlargement in the width of the original, and while scanning drum l makes one revolution, the larger recording drum 3 will also make one full revolution, resulting in a 2:1 enlargement in the length of the original.

By changing therefore the gear ratio and exchanging the recording drum for the desired size, an enlargement, reduction or controlled distortion of the original may be obtained and, by the use of the smudge rejector circuit, a clean and improved copy recorded.

It is understood that other types of variable speed transmission, as for instance friction roller and cone types and the like, will produce the/ same result.

A modified form of the present invention is shown in Figure 4, using the marking bar-helix wire method of recording. In this arrangement, driving shaft 25 is designed to transmit driving power to paper driving roller 28 by means of 65 variable speed transmission 29. While scanning drum 33, recording drum 3I and partly threaded shaft 32, which latter shaft is threadedly engaged to scanning head 33, will rotate at identical speed, paper driving roller 28 is driven at a speed ratio determined by the setting of variable speed transmission 23.

In operation, the output of scanning head 33 is transmitted through an electrical circuit similar to that shown in Figure 1 to the marking 75 6 bar 34. The electrolytic recording paper 35, which may be of standard commercial quality, has the property of producing a mark when current is passed through it, the density of the mark being proportional to the amount of current passed thru it. The markings, penetrating the entire thickness of the paper are of a permanent nature and the paper requires no further processing after recording. This electrolytic recording paper 35 is stored on roller 33 and during operation travels between the marking bar 34 and helix wire 31, and between idling roller 38 and paper driving roller 28, as shown in Figure 4.

The helix wire 31 is disposed helically upon the surface of recording drum 3|, making one full turn on said drum. Means are provided for shortening or lengthening the pitch of the helix Wire 31 along the projected length of the wire upon the drum 3l, said means comprising for example an arrangement using a holding screw and a series of tapped holes disposed axially in said recording drum 3l. The marking bar 34 disposed axially and in spaced relation to the recording drum 3i will produce a mark on the paper 35, whenever current is passed through said marking bar, only at the point where the helix wire passes under said marking bar. At this point, which moves along the full length of the marking bar during each revolution of recording drum. 3l, the marking bar 34 and the helix wire 3'1 are positioned vat approximately right angles to each other.

Electrically, the marking bar 34 is connected to the power ampliiier 2l through transformer 13 and resistances 'il and 13, one leg 19 of the secondary winding of the transformer 16 being grounded 83 as shown on Figure 7. The helix wire 31 is also grounded 3i, as shown on Figure '7.

If a 2:1 enlargement is desired, the pitch of the helix wire must be set at twice the length Ioit' the circumference of the scanning drum 30, assuring thereby a 2:1 enlargement in the length of the original, the recorded copy being displaced by degrees with respect to the original. At the same time, the rate of advance of the electrolytic recording paper 35 over driving roller 28 must be twice the rate of lateral advance of scanning head 33 on shaft 32 due to the action of variable speed transmission 29, assuring a 2:1 enlargement in the width of the original.

In this embodiment of the present invention, a change in the pitch of the helix wire and a corresponding change of the variable speed transmission 29 will therefore determine a resulting enlargement, reduction or controlled distortion of the recorded copy.

It is to be understood that the form of my invention, herewith shown and described, is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of my invention, or the scope of the subjoined claims.

Having thus described myfinvention, I claim:

1. In an apparatus for facsimile recording and the like, in combination, means adapted to carry an original, a scanner producing electrical impulses which vary in accordance with the light and shade of successive elemental areas of equal size along a scanned line on the original, means producing a steady alternating -current signal, means between said scanner and said last named means for modulating said alternating current with the electrical impulses originating in said scanner, said means comprising a resistance- 'capacitance ,bridgeg-fandmeans for manually oontrolli-ng theaamplitude- Aoi the electrical. impulses ,passing'through said-bridge, an aperiodic-,ampli- 'er coupled toisaid bridge,` means :coupled tofsaid ,-ainplier for limiting, thet amplitude of said alternating' current, said'meanscomprising `a pai1. 0f .diodesl means coupledto the anode otonefdiode .andthe :cathode of the other ,diode for. supply- ,.ingxa biasto said diodes,..and resistors coupled --tossaidranode and said cathode formixing Athe loutput of saidpair v.of diodes, means coupled/to said` resistors. foram-plifying the output-.of said diodesffan'd means connected ,to said last, named means4h Ifor recording the alternating signal ...currents received fromsaidlastnamed means.

112.1111- combinationan original .to .be scanned, `.a scanner .producing .electrical impulses which Yaryin accordance VWithcthe ,light .andsshade .Ofi successive elemental areasef equal size along asscanned line onsaid Aoriginal,a recorder, a v .jileofthisipatent transmission circuit interconnecting sadscanner :and said recorder, said transmission circuit com- ,prising asource fof alternating signal Aeurrenuza rent, an vaperiodiaarnplier coupled to. saidirew sistance-capacitance bridge, means eliminating from the alternating signal. current amplitude .:changges ,belowajpredetermined:valuecsaid means comprising a pairf.of-diodes,.the--anode,;of the :firsts-diode .being connected to :the cathodeoffthe fsecondidiode,.afcapacitorgcouplingi the V,anode of .,the'rst .diode :of tneaperiodic fampliern-afretsistorcconnected. between the` common terminal ofssaid capacitor-and said anode and theground, ianiadjustable source ofzbias coupled tor the cath- .Qdervof the first diodeancl theanode of thesecond ,lo diode, resistors connected to the cathodevoffthe rstnliodef and to the-anode oftheA second diode respectively. fcrztlmixingfthe; output ,of said diodes, :and smeanscoupled between said 1resistors and -saidnecorderfamplifying said output 1and transmitting said output to the recorder. K

GEORGE J. GIEL-JR.

.f REFERENCES CITED '.flheefollowing referencesvare of :recordlnjln UNITED VSTATES PATENTS Number Name Date 1,909,142 Zworykin May,.16,i1933 2,108,983 Finch Feb. 22, r1938 y,.2,1(l9,l09 Finch t -.Feb. ,22, 1938 12,136,340 Hardy Nov. 8, 1938 "2,179,002 Washington, Jr .Nov.7,1939 21,227,109 `lShankweiler Dec.;31, 1940 12,251,828 .Harnn'iond Aug. 5,1941 2,301,024 vDHumyv Nov..3, l,1942 12,316,034 Collines, Jr. .May15,19.45 

